Main Site Documentation

Which logic analyzer to buy?


#1

Hello all,

This is not really something directly related to FEZ. But i want to buy a logic analyzer to test results from communications between FEZ and my extension boards etc.

Now i have found 2 boards that are not that expansive:

Bus Pirate http://www.sparkfun.com/commerce/product_info.php?products_id=9544
or
Open Logic Sniffer https://www.sparkfun.com/commerce/product_info.php?products_id=9857

Both look very promising and does what i want to do and do more then i need for now.
Sadly i cant choose which to buy.
Can give someone some reasons why i need to by on of them or do you have an other system that is much better to use?

I hope you can help.


#2

Have a look at the pico scope range :slight_smile:


#3

He is looking for a logic analyzer, not a scope. Last time I checked, the Picoscope guys don’t make a logic analyizer, although my picoscope does has a few serial decoder options build in.


#4

I have seen those pico scope’s in the past but i found that they haven’t a nice pico price attached to it.


#5

How about a project to build a logic analyzer with a FEZ?


#6

Funny I thought about this last week…use the graphical display to make a simple scope/analyzer


#7

Is FEZ fast enough to get some good data then?


#8

It does seem like an interesting project. Of course, even a simple analyzer has some interesting issues to think out.

It would be nice to be able to build one with a less expensive platform than the Cobra. Could use a smaller device and store the results on a SD and then process on a PC.

I have to add this project to the list of future projects.


#9

[quote]Is FEZ fast enough to get some good data then?
[/quote]

Fast is a relative term.

But, it should be able to monitor most inputs and outputs handled by a FEZ.


#10

They’re expensive because they are high quality precision instruments. I have one and I am extremely pleased with it.


#11

I will belief you directly Chris,

But my budget is not that high atm.
So i need to find something in a lower budget market,

I will make my next uLCD project a nice logic analyzer.


#12

You can look into the Link Instruments MSO-19 (find it on Sparkfun). Single analog input scope plus logic analyzer. Runs about $250. Not as nice as the Pico but definitely serviceable.


#13

I have a bus pirate, although admittedly I have not used it as a Logic Analyser client.

Check out seeed studios, they work with Dangerous Prototypes who have started the Bus Pirate and sniffer open source projects.

That’s about $100 less than the likes of a Saelig unit that is probably equivalent.


#14

I’ve got a USBeeSX (www.usbee.com) as well as the Open Workbench logic sniffer (which now Sparkfun also carries.) The software still has a way to go IMHO and the initial firmware revs of the Open Workbench were a bit flakey so I wouldn’t recommend it for the faint of heart. The obvious big plus however is the 200Msps and 100mhz captures at 16channels… though there are other really good pros for it (including other great capture features and multi-platform use.) They are supposedly looking at doing a digital scope add-on for it in the future as well so I’m not done with it by any means :slight_smile:

The USBeeSX caps at 24Msps and can have some capture timing issues on a slower PC (at least it did when I was researching it quite a few sw revs ago), however I find the Windows software works really well. It saved my butt a few months back when a spec sheet from some hardware I got from over-seas said it used SPI, but found it it was only “SPI-like”, LOL. Also helped out a few times isolating I2C issues. I find I use this rather than the OWB board just because I plug it in and it just works and the software works well.

I was torn between the Saleae (my friend has one and raves about it), but I ended up liking the USBee a bit better for some of the protocol add-ons for it that were better at the time. I ended up upgrading to the Pro version of the Software with a coupon code, and like the ability to use the PacketPresenter definitions.

Just my .02.

-Mike


#15

Oh I should also note I believe in my travels I read the hardware for the Saleae and USBeeSX are virtually the same… (a Cyprus chip I believe) the big difference between them is the software. However from you can see, they do copy each other so pretty much look the same :slight_smile:

-Mike


#16

http://www.sparkfun.com/commerce/product_info.php?products_id=9857 is one i was looking at . For the cost to what you get factor it looks good. May just order one this week. To go with my cheap 1 channel oscope travel package.


#17

Hi,

I really liked the ideia of using FEZ as part of a Logic Analyzer !
It’s not so difficult to use a FPGA and some SRAM as a front end to colect, compress and send data to a EMX board. Then write an application to show the data on LCD and to configure some triggers .

Best Regards,

Alessandro


#18

Thanks all for your input.

Not that i now know what to choice but all input is welcome.
I have read all. I was thinking to do the Open Source analyzer.
But reading it is still beta does not help very well.
Also i don’t want to pay to much money for it. So prices above 200 dollar is to much atm.

I will report when i did make my decision.

THANKS again.
And please be so free to add more comments about this.


#19

The DangerousPrototypes guys are awesome, you can’t go past them. Sure, the board may change in future revisions, but they are great. They continue to develop this stuff as time goes on, including the SUMP client, making it better all round. For $50 US plus some cables, you can hardly go wrong in my view. And IIRC Ian is a fellow countryman of yours :wink:


#20

I’m fairly new to the electronics/hardware side of things and nearly quit the hobby because I couldn’t debug simple digital circuits. After doing some research on basic Logic Analyzers, I went with the Saleae Logic ($150).

For me, it was like turning on a light switch. Try out their demo software which runs without the scope. The way it automatically analyzes well known protocols (One Wire, I2C, etc) is fantastic. The software also seems pretty snappy on my several year old desktop.

Keep in mind that I don’t have any other experience with other analyzers, but for what I want to do with the FEZ platform, I’m mainly integrating components together and this analyzer has been perfect to keep my design experience running smooth without requiring me to read a manual to do it.